Year	Percent
1977-01-01	1.4661600000000001
1978-01-01	1.8392600000000000
1979-01-01	3.6857599999999997
1980-01-01	4.1385500000000000
1981-01-01	2.2075099999999996
1982-01-01	0.8804890000000000
1983-01-01	0.7817790000000000
1984-01-01	0.8323700000000000
1985-01-01	1.2616100000000001
1986-01-01	1.3287799999999999
1987-01-01	0.9450230000000000
1988-01-01	1.1453300000000000
1989-01-01	2.1210000000000000
1990-01-01	1.3770300000000000
1991-01-01	5.3996600000000000
1992-01-01	7.9909399999999990
1993-01-01	13.2046000000000000
1994-01-01	15.7082000000000000
1995-01-01	14.4655000000000000
1996-01-01	15.1527000000000000
1997-01-01	17.7465000000000000
1998-01-01	17.4921000000000000
1999-01-01	17.8434000000000000
2000-01-01	17.8898000000000000
2001-01-01	14.7421000000000000
2002-01-01	13.8185000000000000
2003-01-01	20.7641000000000000
2004-01-01	22.9536000000000000
2005-01-01	22.2384000000000000
2006-01-01	20.7594000000000000
2007-01-01	18.7169000000000000
2008-01-01	13.2540000000000010
2009-01-01	11.9460000000000000
2010-01-01	12.7018000000000000
2011-01-01	9.8624400000000000
2012-01-01	6.5320400000000000
2013-01-01	7.2814200000000000
2014-01-01	9.2306100000000000
2015-01-01	9.1128900000000000
2016-01-01	9.1628600000000000
2017-01-01	12.9724000000000000